Which Flowmaster is the best application

I’m ready to purchase Flowmaster mufflers for my 70 Cuda 440+6 and was looking for some input as to which of the following you have had experience with: 40 series, super 40 series or the 44 series.

straight pipes [saves lives ya know] [JK]

Buy the reproduction factory mufflers, they sound better.

Agreed

Have the Flowmaster 40 series on my GTX and can't stand the resonance at any cruising speed and my wife rarely wants to get in the car for anything but a very short trip. She says it gives her a headache and liked the Dynomax stainless Ultra Flo mufflers on the '68 Road Runner much, much better. Me too hands down. The Dynomax mufflers are the same design as the stock OEM mufflers and they sound to me exactly as I remember what the mufflers on my new in '69 Road Runner sounded like in 1969......I'm old but that's what I remember them sounding like for the 11 years of ownership. First time I drove the GTX with the Flowmaster's I stopped the car to see if there was a problem with the mufflers like a loose clamp or something. Bought a new set of Dynomax ultra flo's and can't wait to put them on....the Flowmaster resonance is painful some times.


My Road Runner circa summer 1969

Can you say "drone"???

I got on the Dynomax website and did not see any Mopar applications, only Ford and GM. Tell me what Dynomax muffler you put on your Road Runner. Do you have a 2 1/2 inlet and 2 1/4 outlet?

I put a pair of the stainless flowmaster fx on my 5.7 magnum... not loud, but they sound good. Probably would be louder on a car without cats.

Correction on the inlet and outlet positions; Offset in/Center OUT



The mufflers I have are 2-1/2" offset in and 2-1/2" center out.

The Dynomax official site shows it as center in and out which is incorrect. Every other site shows it as offset in and center out both with 2-1/2" diameter. Part number 17289

Found this just now on the Advance Auto parts site for $195.99

Dynomax Ultra Flo SS Universal Muffler part # 17289




This is one of the box labels on the mufflers I have (dimensions are on the label in inches):

Mike

Mike,illustration is wrong,description is correct.Also if tailpipes are correct they would be 2 1/4" same as B-body so that means a tail pipe change with this muffler


17289
ULTRA FLO™ STAINLESS STEEL POLISHED - OFFSET / CENTERED
Muffler Configuration: Offset/Centered
Inlet / Outlet Diameter: 2.5"

And on aside note,personally I wouldn't put a Flow Master on my John Deere,but that's just me !

Thanks Bill, as always you're on it. I never considered the stock pipe size for my rr or gtx and always intended to run 2.5" pipes in and out. Are O.E. pipes 2.5" in and 2.25" out or 2.25" in and out?

Thanks Bill


Mike

This,

O.E. pipes 2.5" in and 2.25" out

Flow stoppers are a big NO NO if you want the most performance from your ride
Buy a set like in the one post showing the perforated pipe coming in on the side and going straight through the muff to the outlet in the center That design has the least restriction

Yeah Bill that JD of yours is way too nice to do that

If your going to drive the car less than 300 miles a year it doesn't matter but I've used the 40 and 44s the drone sucks.

In 1994 I was 24 years old. Put 50 series FMs on my 440 Challenger. Holy crap I hated it. Friends loved the sound but my killer stereo had to be cranked up LOUD just to hear inside the car. A lower HP car with OEM exh manifolds will not be so crazy loud but Powerful a engine with headers...Flowmasters are an eardrum cracker.

dynomax!

Come to think of it I put a 50 on my 05 four half ton Dodge pickup and that sucked.

Love the Original 40 Series on my car. Loud and Proud

I run 3" super 40's on my hemi and love them.

Do you want noise, or mufflers that actually flow?

Dynomax super turbos on all my cars never had an issue runs good too.

http://www.pontiacstreetperformance.com/psp/exhaust.html

Wow, I recognize that article!
Tom Hand

A few surprises with that article thanks for posting. One surprise was the performance and sound level of the Supertrapp mufflers! Pretty much knew the Dynomax mufflers were much better all around over the Flowmasters hands down in almost all of the categories. There was a Moparts member a few years ago that changed his Flowmasters at the track (on the same day IIRC) to Dynomax and picked up several tenths in the quarter. I think there were no other changes during his testing other than the mufflers. Probably could have picked up a little more with jetting but the bottom line was the Dynomaxs' out performed the Flow's in his swap. Don't get me wrong the Flow's have that cool tin canny likable muscle car sound at idle and a pretty nice aggressive sound at wide open throttle BUT the drone at anything above or below those two points is unbearable, so bad that I have to push the clutch in or stick it into neutral and coast for a while to recover from the pain. Wonder what the Supertrapp's sound like...have a couple of bikes still with the Supertrapp mufflers and they sound good Hmmmmmmmmm probably have enough STRPP parts around to make a pair

Okay, you guys have changed my mind, i ordered a pair of Dynomax Super Flo’s. Thanks for all the constructive comments and experiences.

Here is the inside of a Super Turbo. I think I found this picture on here and saved it. I don't like the way the exhaust flows right into the exit pipe. For low hp applications it probably doesn't restrict the flow much but I wouldn't want to use them on anything that is making good power. I'm not really a fan of the sound of these either. Exhaust sound is a very subjective thing.

go read the article linked above.

Unless I'm missing something, both Dynomax mufflers listed in the article are offset inlet and outlet. Those are designed differently inside. The center outlet design is the one that looks restrictive.

Not really - they simply cross-flow internally. The sCFM #'s for offset/center, & offset/offset are about the same - around 410 sCFM's for both 2.25" & 2.5" Super Turbo versions. Still, Super Turbos do not do much "tuning" of the sound, but they do more than Ultra Flows. Ultra Flows are like oval glasspacks & other straight-through mufflers. Flowmasters TUNE the sound, but they do not flow impressive sCFM's because the plates internally cause quite significant restrictions.

Here is a link that should show how the exhaust is routed in an offset inlet/outlet Dynomax. With this design the exhaust doesn't have to flow around the outlet pipe like the center outlet design. It may flow just fine but it "looks" like a restriction.

http://www.dynomax.com/mufflers/super-turbo-mufflers

I wouldn't run that type of muffler on any of my cars due to the exhaust having to make two 180 degree turns in a short length to get out of the mufflers

I ran FM 10 series on my fury for a number of years, what's all this complaining about their big mufflers 😎
I do have summit turbos and tailpipes now, plus the turbos themselves, much different now.

Awhile back when the report came out about flow rates of the popular mufflers, I read responses from the Flowmaster reps...."Ah, forget those tests....engines flow differently than the testing methods did."
I have the Welded Ultra Flo mufflers on my Charger. I had Flowmasters before. I did like the WOT sound of the Flowmasters but grew tired of the sound at all other times.

Dynomax Super Turbos are restrictive as he11 and definitely hurt power!
I like Flowmasters personally, but know a lot don't.
Never seen the performance drop from Flowmasters a lot claim though. Had a set of 3" 40 series Flowmasters on my cuda w/ a 440 that ran 11.40s in the 1/4 and it ran the same w/ the mufflers or without them.

The Dynomax Ultra Flow, Hooker Max Flow, or Hooker Aerochamber are very good flowing and sounding mufflers too.

I had Flowmasters on my 70 B-body, and the drone at highway cruising RPMs was AWFUL.

Switched from manifolds to headers, then switched from an H-pipe to and X-pipe while keeping mufflers the same. Got a little better, but still droned badly.

Your mileage may vary, but I would not use them again.

Some time ago, Michigan state university did a muffler comparison and put out this chart.

Crap - it didn't attach the chart......

I think I've ran em all lol
I tossed Dynomax Super Turbos on my daiy driver Cordoba, 2 1/2" mandrel bends out the rear coming off Hooker SuperComps. Love the sound honestly. No drone, nice sound and fairly quiet at cruising speeds.
Best Flowmaster sound I have heard was my motorhome, I loved it. Healthy hydraulic roller 360, headers, Y-pipe into SINGLE 3" exhaust and two 3" Flowmaster 50 series in TANDEM.
I loved it. Quiet and gorgeous tone, no drone.

It took a couple tries but I felt I got it perfect on one car, I loved the sound of the 2.5" 20" super turbos on my 5.7 magnum r/t daily driver (manifolds, jba catless mids). I also tried 2 chamber flowmasters and hooker aero chamber on it. flowmasters were too loud for long drives for my taste, hooker was slightly quieter but still just a little too much sound. The 20" dynomax required some light fab work to fit, but I liked them the best. The problem with alot of late models is most exhaust for them is spec'd with cats which kill alot of volume. Go catless and suddenly everything is louder and more droney.

I loved the sound of hooker aero chamber 3" on my GTX when I had H pipe, 1 and 7/8 comp headers, and almost the same engine combination as now. However I was chasing power so I went slightly bigger and with ultra flo. I also like those quite a bit. the power thing worked out ok in conjunction with other changes.

For short blasts in a hot rod I'm ok with the classic flowmaster thing, but they better be pretty short drives. To jump in and drive for a couple hours, I'd have to go with old-man 20" super turbos. I believe these are what used to be marketed as hemi super turbos....

I have Flowmasters on my 440 Power Wagon. They actually sound good in that application.

THIS is what I felt like after a long drive with the Flowmasters in the Charger:

Let us know how you like them once installed ? I personally like the flow master sound and I’m wondering what you think of what you ended up ordering.

Just by the air flow and sound level the Dynomax Ultra Flo's are in a league by themselves 101% flow I thought that isn't possible. 1% more flow out than in

Well, the Dynomax are not going to fit, way too long for the Cuda. So going back to the Flowmaster 40 and then run a couple of short glasspacks near the tailpipe extensions. Wish the Dynomax would have worked, but I am moving on.

If you're going with flowmasters get the super 40 they are a lot quieter on interior noise.

They make different sizes, I can’t see why you can’t get one to fit.

Yep,if the make a Flowmaster to fit they also make a Dynomax ,just look in the right place!!

Searching Summit, they show Dynomax Ultraflows case sizes in 14, 18, 20, and 24 inch lengths.

The 17289 recommended on the first page are 20".

Everytime I read one of these muffler threads I always wonder why no one recommends Borla's. They are just like the ultraflows but don't have the history of blowouts or other defects. They are a great flowing muffler, sound awesome, and last forever. Just wondering...

I run a pair of Borla ProST-mufflers on my '73 Dart.

I'm running Flowmasters 50s which is the quietest one they offer. On my 70 Dodge Charger. Is a 3-inch TTI full headers and exhaust. Personally it sounds good from fifty to a hundred feet away. On my son drove around the block oh was it sweet. But in the car it's a tad on the loud side. Which brings me to my next question since we're on a muffler post.

I would like a quiet as in real quiet Muffler. What would you guys recommend? ,( I don't mean Buick quiet, but close to it because quite frankly I'm getting old. And I'd rather hear the radio).

I've got a pair of Flowmaster 50s under my '62 NewYorker wagon.
It has a stock diameter exhaust and the engine has carboned-up the mufflers pretty good to have given them a fairly toned down sound.
I kinda like it because when the engine is idling or when driving you can hardly hear there are Flowmasters under the car. It only is noticable when getting on the throttle.

I have Flo Pro originals, which is kind of like a welded turbo muffler with no packing. I like them. They might be too loud for people who want to listen to the radio in the car. The muffler shop refused to put on anything else after I blew up a Cyclone Sonic Turbo. That was a long time ago.


Naybor got one of those must4ngs with a muffler delete, so I was going to get Pypes Violators. He got a quieter system tho, so I left the Flo Pros.

I read the chambered mufflers like a Flowmaster for some reason get really hot. Don't know first hand if that is true or not.

Flowmasters...if it's to loud you're too Old...

Open headers if it's like that.

I've always wondered...

When you're getting old, most likely you'll become hard of hearing too.... Wouldn't that be a reason to start appreciating FlowMasters a bit more?

In my book the FlowMaster mufflers are more of a senior citizen muffler...

Because Borlas are stupid expensive and I've never had any issue w/ the cheaper brands "blowing out".

I put Ultra Flos with a 20 inch case on my car to replace some Thrush Hush Turbos with a 14 inch case (very similar to the Dynomax Super Turbo). The Ultra Flos are actually quieter.

This is with 3 inch pipes, and those Thrush Hush necked down to 2.5 or less internally.

I'm very surprised at how quiet the Ultra Flos are with the long case. I had 14 inch case Ultra Flos on it before, and it was too loud to hear the motor (fresh motor), which is why I band aided it with the cheap Thrush Hush. Really, you would not think that this car has straight through mufflers with 3 inch pipes dumped at the axle now, except at WOT.

Just changed over the Flowmasters this morning. Went with a generic turbo muffler. A lot quieter, no drone and has a nice rumble.

Brother had a friend who had a Camaro with Flowmasters on it and the car picked up several tenths once he removed them. People buy those based on what they sound like. Nobody I'm aware of that has a dedicated race car uses those things. They are very popular with Mustang and Camaro guys for some reason.

Hooker Aero Chambers are good.

I don't like mufflers with packing material in them. They end up getting louder over time. Motorcycles come that way and you have to rebuild the mufflers every so often. Can't do that with a sealed car muffler.

I don't believe muffler flow bench numbers and I don't believe cylinder head flow bench numbers. Some made up machine cannot duplicate the airflow capacity of a running engine.

Hmmm...sounds like the words from a guy representing Flowmaster!

Well, you're likely right about that, specifically. But a "made up machine" CAN produce airflow, measure the amount of airflow that it produces, and measure resistance put on it by (in this case) a muffler. You can, however, argue how that measured resistance affects an engine's performance. Actually, I take the last part back.

Flowmasters sound good on fox body 302 mustangs. They had a unique sound to them on the roller 302.
I have ran them on 340's but they are loud for sure. Now im running TTI exhaust on both of my cars and the dynomax super turbos that came with the kits.
I can say one thing about these mufflers. When I first put them on I did not like them much. After about a month or two they got a little louder and sound really good.

anyone try the MF = magna flow?

I run a single 2.5 in/out offset/center one on my 98 grand Cherokee 5.9

I liked it a lot and thought I would swap out the cheap FM knock offs. which do sound ok on my truck and are not loud but not the tune I like.

Purple Hornies are still available....

I have been running the DynoMax mufflers on the Plymouth for years, great sound and holding up well, no interior drone to speak of.

Regarding Magna Flows I am running one on my Diesel and it has been great, nice flow and build quality, nice sound and not loud. Not sure about their Muscle Car applications though.

Magna Flows are cheaper knock-offs of Dynomax Ultra Flo welded - they used to be called "Race Magnum" series. They don't do ANY tuning at all as the exhaust passes through. To me, they sound FLAT, but get louder under WOT.

I have always have at least one car with a pair of Flowmasters on it since around 1985. Mainly because they were always cheap. No seeing the actual flow data I may have to change them up to some Ultra Flows.

so, what about tests on a car?http://www.pontiacstreetperformance.com/psp/exhaust.html

Tests on a car, the same car, is as believable as it gets.

Best flowing muffler would be something crazy like a 5" race bullet. Does not mean that muffler is right for most applications, or would even make it a car run any better if it's just the wrong one to pick. People take the whole flow bench stuff too seriously. It's just a tool to measure change or differences between things, but it can't tell you what it will do on a specific engine, at a specific altitude, at a specific rpm range, ect. It's all about a combination of parts working together that you have to look at.

I can say the Aerochambers are good because my brother has them on a low 11 second car and it runs very close to the same with them off. So much so that it's not worth the effort to remove them. They are a baffled muffler that won't score high on a flow bench, but on a running car they do what they say they do.

Did you read the link?

Nope, pressed send right before leaving work. Just finished reading it now.

Dynomax mufflers work well. Only thing I don't care for is the insulation inside that can break down over time. In an old car that isn't driven a lot this is a non issue.

Interesting how the Supertrapp does everything just as good, or better in the case of a flow bench reading, than the Dynomax, but ends up being one of the 3 loudest. I would never buy a Supertrapp muffler for an old car, but I do like the fact that they are serviceable and adjustable. They are very popular with dirt bike and ATV racers.

The Borlas flow bench within a hair of the Dynomax, but are a 'slower" muffler down the track.

Muffler companies don't seem to talk about decibel control as that's not as sexy as flow rate, or the type of patented aggressive sound they produce. If they came right out and said our mufflers are super quiet, most would think that would mean a loss in power.

Not trying to bust any chops but I don't quite get this response as Magnaflows and Borla Pro XS's are both within a few dollars of each other at Jeg's and Summit. The XR-1's are quite a bit pricier, but that isn't what most guys would run anyways. I've strayed from Borla's a few times on some different projects but always wound up coming back to them as they fit all my needs. Great sound at idle, mellow enough when cruising, bark when getting on it, have minimal impact to my E.T., and last forever. I just switched back again after letting someone con me into getting Flowmasters and probably will never stray again. I guess this is why there are so many brands out there. Exhaust is very subjective for sure. :-)

I'd like to point out that in our chart, when you see StraightLine Performance, those are Magnaflow mufflers.

Another very important point is that the mufflers we tested (those with chambers and "V"s inside them), were offset in and offset out or center out. The first jog the exhaust gas has to take to get into those mufflers really affects its flow. And it should as the exhaust gas pretty much hits a flat surface as it first enters into the muffler.

All the cars we tested them on acted the same way, performance dropped compared to straight through or center in mufflers. Center in versions of chambered mufflers work much better although the sound level did not change much. Hooker Aerochambers, when offset in (are made differently) flowed better and ran better than some others.

We tested other mufflers but chose not to share them in this chart since we were doing mufflers that typically are used on street cars. At the time, very few cars used center in and center out rectangular or oval mufflers so we did not publish results.

We learned that overall, it was pretty simple: when the air can get in and out smoothly, the power level seemed to stay higher. When the mufflers had sound "absorbing" materials in them (more so than only stainless steel) they were quieter. So, combine a good perforated tube pattern, high flow potential, and good sound "absorbing" material and you get sound control, nice sound, and better performance. In other words, you get a muffler that truly muffles and ones that let the engine run well and the car perform at the strip. If you need more sound or roar or rumbling, it is often a tradeoff with power output but, in life, it's all a tradeoff anyway right? :):)

Tom Hand

I like the way my 40 series flowmasters sound on my Challenger with an H-pipe, they are a not for everyone though and are a bit loud. I do plan on an x-pipe and ultraflows for my charger though just to mix it up and have a different sound/pick up some hp.